Looking for a proper rear diffuser.

[0100]

Looking for a functional rear diffusers for an e90.

These look like they may actually do something, but who knows???

Fancywide
Mkah
Varis
ECS

Are there any others out there?

[MineralWhiteF80]

I'd love to see some real-world testing of the available diffuser options for the e9x. I don't know if they are helpful or hurtful. I don't know about "proper," but here is another company I found a while back.

Aeroflow Dynamics:
https://www.aeroflowdynamics.com/pro...63c7c331&_ss=c

[omgzirra_exe]

rear diffusers are useless unless you have a full flat bottom set up.

[roastbeef]

Originally Posted by omgzirra_exe

rear diffusers are useless unless you have a full flat bottom set up.

this. the air is so messed up that by the time it gets to the rear diff/subframe area, that a diffuser back there has little effect. might help keep air out of the back bumper if you have an aftermarket exhaust, but that is about it. airflow isn't just going to start adhering to a smooth surface because it is there. it starts at the front.

[Estoril Blue]

Originally Posted by omgzirra_exe

rear diffusers are useless unless you have a full flat bottom set up.

This 100%

[0100]

Great thanks guys. Saved me some money.

Doesn't look too hard to make a full flat bottom though...

[okusa]

Originally Posted by 0100

Doesn't look too hard to make a full flat bottom though...

It doesn't?

[omgzirra_exe]

Originally Posted by okusa

It doesn't?

must be an aero genius lol

[0100]

Maybe it's because I work with sheet metal a lot, but building something like this does not seem hard.

https://pbs.twimg.com/media/C4UP3keWAAIy_ZF.jpg

[DRLane]

Originally Posted by 0100

Maybe it's because I work with sheet metal a lot, but building something like this does not seem hard.

https://pbs.twimg.com/media/C4UP3keWAAIy_ZF.jpg

Please keep us posted if so! Managing the exhaust heat will be the biggest obstacle. I know Zebulon made a carbon flat floor and diffuser for one of us. But the heat will be a challenge.

[omgzirra_exe]

Originally Posted by 0100

Maybe it's because I work with sheet metal a lot, but building something like this does not seem hard.

https://pbs.twimg.com/media/C4UP3keWAAIy_ZF.jpg

if i can make a front splitter i can do a flat bottom, so i understand what you wmean.

the problem with making the flat bottom is making sure the air is doing what you want it to do properly.

[M3SQRD]

Here’s a prefab’ed e92 M3 used by JP Marketing with good results in time trial events.

https://www.jpmarketingllc.com/produ...r-recaro-racer

I’d recommend the use of a diff cooler when using a functional diffuser.

[0100]

Great info guys, glad I started this thread.

That JP diffuser looks like the ticket!!!

Yeah and I didn't even think about exhaust heat....

Definitely not going to be as easy as I first imagined.

[DRLane]

Originally Posted by 0100

Great info guys, glad I started this thread.

That JP diffuser looks like the ticket!!!

Yeah and I didn't even think about exhaust heat....

Definitely not going to be as easy as I first imagined.

Here’s a must read thread: https://www.1addicts.com/forums/show....php?t=1713247

[omgzirra_exe]

Originally Posted by DRLane

Here’s a must read thread: https://www.1addicts.com/forums/show....php?t=1713247

speaking of which mr redpriest just finished his flat bottom.. and it purty.

[0100]

Originally Posted by DRLane

Here’s a must read thread: https://www.1addicts.com/forums/show....php?t=1713247

Wow that is an awesome thread, thanks!!

[redpriest]

Since we're talking about diffusers and flat bottoms, here's mine. All in it cost me probably $23k to do. The dirty secret about flat bottoms is that you need to figure out something for your diff cooling as well as reroute the exhausts so it's not so low.

This means you have to probably create a custom exhaust. Here's mine:

gold reflective tape to protect the carbon:


Custom exhaust mufflers - i went with titanium/stainless steel construction




Diff cooler reroute:


Laguna turn down tips:


Flat bottom on the car with diffuser:


Aluminum plate covering the engine cover and replacing the brace, looking aft past the transmission:



The diffuser itself:

[TheStevo1000]

Damn, that's impressive. What were the results? Big lap time difference?